This invention is directed to a system and method to generate a two color rendering of images, such as images which use a single color hue, which is not black. The system is particularly advantageous in connection with obtaining printouts of two color images which are used to give a desired effect or look. However, it is to be appreciated that the disclosed system is advantageously employed in any electronic document rendering system in which a simple and effective mechanism for constrained color rendering is desirable.
Typically, image data is encoded into a form wherein color is represented by values in a selected color space. For example, common encoding is done in a primary color space, which is suitably additive, such as red, green, blue (“RGB”) or subtractive, such as cyan, magenta, yellow (“CYM”), the latter of which is often coupled with black (“K”), resulting in CYMK or alternatively, CYM(K). Sometimes, for effect, it is desirable to render images with a limited color palette. In the case where an image is rendered with a dominant hue, it is referred to as two color, bi-color, bi-chromatic or twin color mode, which are understood hereinafter to reflect the function of the subject teachings. Two color rendering is suitably defined as generating an image with a single, non-black hue.
There is a need for an effective mechanism to achieve two color printing from color printers, particularly in connection with prints obtained from multi-function peripherals. This requires a mechanism that allows for derivation of two color rendition using conventional hardware available on document output devices.